Function create_external_buffered_stream 

pub fn create_external_buffered_stream<T, S, P>(
    stream: S,
    path: P,
) -> Result<impl Stream<Item = T>, Error>
where
    T: ExternalBufferSerde + Send + 'static,
    S: Stream<Item = T> + Send + Sync + 'static,
    P: AsRef<Path>,